As to weight loss, you'll find that everyone's "mileage" varies, depending on how strictly they control what goes into their mouths, how much they exercise,
how they exercise, etc. It is not uncommon for people to lose anywhere from 5 to 15 pounds (or more) within the first month or so of following a paleolithic way of eating. Some people, especially those who are more drastically overweight to begin with, commonly lose a greater amount of weight in the beginning. If you want to get a good picture of what this lifestyle can do for you, check out the "Success Stories" section on the website called Mark's Daily Apple (link below).
Good luck, and let us know how it goes for you!
http://www.marksdailyapple.com/the-book/success-stories/